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SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '09d2a4e2d70696714b2b4ce4f6c083d9bae792f70159f834b44bff56ebc3564f' 
  AND token = 'ddiA7cU6Rd5ckWrzsKGlRU21SmQ0frnAnaK+e3HX0wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}